Anticans were a carnivorous species who preferred to eat their meat alive, and they had no compunction about killing and eating their rivals, the Selay. They killed their food using small weapons which projected a short energy blade.
In 2364, the Anticans applied for membership to the United Federation of Planets. The USS Enterprise-D transported their delegates to the planet Parliament to help resolve a long-standing dispute with their sister planet, Selay, as part of the admission process. (TNG: "Lonely Among Us")
Background information Edit
The dog-like Antican species was designed by Concept Artist Andrew Probert. As such, it was one of only three alien facial designs that were conceived by Probert prior to Makeup Supervisor Michael Westmore joining the production crew of Star Trek: The Next Generation, the others being the Ferengi and the Selay.
Although Gene Roddenberry decided (at about the start of the series) that all aliens shown on TNG were to be depicted without burying the actors under deep rubber or covering their mouths, the Antican makeup – involving a pull-over mask – broke this rule of thumb (in common with the makeup for the Selay and Armus). (Star Trek: The Magazine Volume 2, Issue 12, p. 26)
According to an internal reference document, listing all the aliens seen in Star Trek: The Next Generation, which was circulated around the time of the production of TNG Season 5, the Anticans were given the description of "canine-like face, leathery skin and enlarged rear craniums. mostly bald."